Clinical review 122: Parathyroid carcinoma.

Parathyroid carcinoma is an uncommon cause of PTHdependent hypercalcemia. The collective published experience with this rare neoplasm has provided a distinctive clinical profile that differs in a number of respects from that of benign primary hyperparathyroidism (1–3). The distinguishing features of parathyroid carcinoma assume even greater prominence when viewed within the current context of primary hyperparathyroidism, which commonly presents today as a mild asymptomatic disease (4–8). In this report, the clinical features, natural history and prognosis of parathyroid cancer are reviewed. Surgical approaches to parathyroid cancer are outlined as well as medical therapies of the hypercalcemia that accompanies recurrent or metastatic disease. As the ultimate prognosis depends to a major extent upon successful resection of the tumor at the time of the initial operation, major emphasis is placed upon those features of parathyroid carcinoma that help to differentiate it from primary hyperparathyroidism due to benign adenomatous or hyperplastic disease.